1. Field of the Invention
The present invention relates to a buffer and an organic light emitting display using the same.
2. Description of Related Art
Recently, various types of flat panel display devices have been developed. These flat panel display devices are generally lighter in weight and smaller in volume than comparable cathode ray tube displays. The flat panel display devices include a liquid crystal display, a field emission display, a plasma display panel, an organic light emitting display, and the like.
Among these flat panel displays, the organic light emitting display displays images using an organic light emitting diode (OLED) that emits light through the recombination of electrons and holes.
An OLED used in an organic light emitting display includes an anode electrode, a cathode electrode, and a light emitting layer formed between the anode and cathode electrodes. In the OLED, if current flows in a direction from the anode electrode to the cathode electrode, light is emitted from the light emitting layer.
Such an organic light emitting display displays images using the characteristics of the OLED. The organic light emitting display includes a plurality of pixels each having a thin film transistor (TFT) and an OLED. An amount of current that flows into the OLED is controlled by the TFT to express luminance.
Currently, the size of an organic light emitting display is becoming larger. In order to decrease manufacturing costs of organic light emitting displays (that may be relatively large), a plurality of flat panel displays are formed on a large-sized bare glass substrate and then the substrate is cut, thereby completing respective organic light emitting displays.
After pixels are formed on the bare glass substrate, a test such as a lighting test or the like is carried out on the bare glass substrate so as to inspect whether each of the pixels operates properly. Since a large number of pixels are formed on the bare glass substrate, a large number of resistors and capacitors are also formed on the bare glass substrate. Therefore, a signal delay may occur due to the resistors and capacitors.
Such a signal delay may cause a driving failure of the organic light emitting display.